Insulated-wire stripper



March 6, 1928. w

. 1,661,180 1.. JOHNSON INSULATED STRIPPER Filed Sept. 10. 1924 IVl/E/VTU/F Lawrence 74/7/7100 Patented Mar. 6, 1928.

UNITED- STATES ATENT-0mm LAWRENCE JOHNSON, or CHICAGO, .ILLINoIs, AssIoNon rozrorrnson a wnm'mx, or CHICAGO, ILLINOIS, A PARTNERSHIP, CONSISTING or LAWRENCE JOHNSON m ALFRED N. WENT INK.

INSULATED-WIRE STRIPPER.

Application flled s epte mber 19,1924. Serial No. 786,848.

" i This invention has relation to means for removing the insulation from tliefends of electrical light and power conductors.

Various machines of this type ,have been devised, of which some have reachedthe market. In all such machines, so far as I am advised, two operations are required in order to strip theiinsulation' from the end of an'insulated wire. In someof these machines the stripping knives commence to close automatically on the insulation when the machine begins to rotate, but it is neces sary to stop the machine in order to open the knives, so as to be able to insert another wireend. Othersrun continuously, but on such an extra hand or foot operation is re quired to close the knives on the conductor, and again to open them.

The principal object of the present invention is the provision of a fully automatic machine,by Which'I mean a continuously running machine, into which it is onlynecessary to pushthe wire end the desired distance and quickly to withdraw it stripped of its insulation. Sucha machine is here-' inafter described and illustrated in the appended drawing, of which :1 I

Fig. 1 is a sectional side elevation of a structure embodying the invention,

Fig. 2 is a corresponding front elevation of the device with parts broken away for the sake of clearness, i f

The invention in the form illustrated is supported on and driven by an electric motor -1, on the armature shaft of which is clamped a bifurcated head in any suitable manner, as by a setscrew 3. This head, 2, supports apair of oscillatory frames 4 and 5, mounted to swing axially upon suitable pivots 6, and these frames are shaped to receive a pair of knives 10 and 11, the opposed cutting edges of which are directed toward the axis of the head. Across the front of the bifurcated head is rigidly mounted a strip 12, and this strip is centrally perforated to receive a guide bushing 13.

The foregoing short description is suflicient to explain the operation of my device. In order to strip the insulation 15 from a piece of wire 14it is in the first instance necessary, to start the motor, thereby causing the head 1 torotate. Now it is noticed that the portion of the knife frames lying outside the pivots 6 are larger and therefore heavier than their innerportions, as a consequence 66 will remain until the motor again is stopped oruntil the. wire 14. is'pushed through the guide 13 and against theyielding inner ends of the knives 10,11. As the knives will yield tothepressure of the wire,.the latter iscarried forward between the knife edges as far as desired, as shown in dotted outline at 16,. compelling the knives to take the position shown in full outline. But the moment the operator pulls on the wire to withdraw itit is to be observed thatthe knives will begin to right themselves again, and a continued pull on the wire permits the knives toresume theirupright position, thereby bringing'their cutting edges sufficiently togetherto penetrate the insulation of thewire, which then is fully withdrawn, leaving the stripped insulation free to fly out to one side; This single operation needs to take only two seconds.

In order that the knives may cut evenly it is Well to combine them. in such a manner that one will follow. the other, and this may beiaccomplished in the manner shown in the drawingsto comprise a pair of gear segments 17, 18 rigidly mounted on the sides of the knife frames 4 and With such intermesh ing segments the knives are compelled to move together andto cut evenly. The knives should be longitudinally movable in their supports, in order that they may be adjusted to. operate on conductors of various diameters, and this mayconveniently be done by seating screws 19, 20 in screw threads out into theiouter ends of the knife brackets, and by providing these screws with annular flanges 21', 22, which in turn .fit intotransverse slots 23, 24 in the outer ends of the knives. After once adjusted the knives are clamped in position by set screws 25 and 26- The device of my invention is not required to rotate at any great speed, in fact it will function perfectly when rotated by hand, but where it is mounted to rotate with the armature shaft of an electric motor, it is compelled to operate at a much greater speed than necessary, And as it is very dangerous to have such high speed structure exposed while in rotation, I have provided a suitable stationary cover 30, which completely drop out of the way.

encompasses the head. This cover is shown forced on to the bearing and commutator and such gauge may take the form shown in thedrawing to comprise an anglebracket 34, held by a screw 35, and pi'ovided'with a graduated scale 33, by means of which the gauge may be set to a predetermined length. I also reserve the right to introduce other modifications, so long as I remain within the scope of the invention, as here inbetore outlined.

I claim:

1. In a wire stripper, a continuously rotating head, a guide :t'or the nsertion of wire to be stripped, and cutting members pivotally hung to swing axially within said head,.said members by centrifugal force urgedinto a plane transverse to the axis of the head, the members axially yielding to the incoming wire but returning to their initial position upon withdrawing the wire and turning;

penetrating the insulation while thus re- 2. In an'insulated wire stripper, a continuously rotating head, a guide for the insertion of wire to be strippech and cutting members pivotally hung within said head, said cutting members maintained radially directed by centrifugal force, tree to swing.

' axially under the pressure of a Wire inwithin the bifurcation of, the head with,

serted through said guide aiidfto return to the radial position upon Withdrawal of the wire, the cutting members penetrating the insulation during this return movement.

3. In a wire stripper, a continuously rotating bifurcated head, awire guide concentrically mounted on the head, cutting members pivotally mounted to swing axially their cutting edges directed toward the" axis of the head, and their outer ends sufliciently heavier than their inner ends to cause the centrifugal force to, swing them axially into radial position,

4. In awire stripper, a continuously ro- 'tating head, a wire guide,cutting members pivotally hung in said head and having their cutting edges directed toward'the. axis of the head, said members free to'yield' axially to the pressure of wire iiiserted'through said guide, but returning to their initial position and s multaneously penetrating the w re insulation upon withdrawal of the wire, and

ineansadjusting said members to the thick-,

ness oi the wire to be stripped.

5. In a wire stripper,la continuously rotating head, a wire guide, cutting members within the head with their cutting edges directedtowaid the axis of the head, said members free to swing axially when pressed upon by the wire inserted through the guide but returning to their initial position upon withdrawal of the wire and cutting through the wire insulation during this return movement, and a stationary cover totally eiiclosing the mechanism described-" a 6. In a wire stripper, acoiitinuously ro tating head, trainespivotally seated in said head, knives adpistably seated in said frames with their cutting edges radially directed toward the axis of the head, said frames free to he turned axially by the wire to be stripped, but returning to'their initial piosi-i tion upon withdrawal otthe wire simultaneously penetrating the wire insulation, means interconnecting said frames for simultaneous rotation, and a stationarycoyer encompassing the entire'mechanism.,

7. In a wire stripper, a continnously'rotating head, fraiiies'apivotally mounted in said head, knives seated in said frames, said traiiiesby "centrifugal force maintained radially directedwith the cutting edges of the knives near the axisof the head, screws in the outer ends or" theframe's, said screws engaging slots in the knives for the purpose of ad usting the latter, and means clamp ingthe knives in ad usted position.

In testimony whereof I have hereunto at- I ilXGCl my signature.

' [LAWRENCE JQHNSON; 

